What's Happening Today - Nov. 25

As the DSL-120A sonar fish was being hauled up this morning from its last survey line, the folks on watch were plotting the many ways in which they would hack off the end of the cable; thereby signalling an end to the use of the sidescan sonar for this expedition. The sonar has functioned terrifically this cruise. As usual there were some tense moments, and considerable learning about how to operate this new system and what improvements need to be made. But, the bottom line is that the DSL-120A sonar produces unmatched images of seafloor terrain in the deep ocean at a resolution of about 1-2 meters - the size of your dining room table. This gives us marine geologists the ability to 'pull-the-plug' on the ocean basins and "see" the terrain that lies beneath the waves. In the next few days, as we make preliminary maps of the areas we've been studying and mapping, we'll post the sonar imagery in the data section of this web site.

What continues to amaze me is that as we are surveying with the sidescan sonar, or collecting rock cores or towing the camera THING, ABE is "On The Job For Science", humming along at 2 kilometers/hour making the highest resolution maps academic scientists have available to them for this area. Pretty incredible. As I write, we're waiting for ABE to finish Dive #58 and in the meantime Brent Garry and I are rock coring.

Later tonight we'll do more rock coring and another camera run over the area we plan to have ABE survey during the next few dives in our southern survey area near 9° 29'N.

Check out the new map of ABE tracklines in the 9° 50'N area- Dives #54 to #57 in the

Preliminary Data section.

Big News: Less than a week left to go on station.

Best Regards,

Dan Fornari

Ed 'Catfish' Popowitz, an Able Seaman, at the controls of the traction winch in the "Dog House" on R/V Atlantis.

Brent Garry looking very pleased with himself for doing such a good job on the rock coring last night. Dan Fornari is in the middle, and Dave Sims, one of the SSSG techs. is directing the operations.

Michelle Cooper processing samples from the rock coring last night. She's scooping the wax out of the stainless steel cutters that slammed into the lava flow on the seafloor. The wax is placed in a paper cup with some water and put in a microwave to heat up so that the wax melts. The wax and water mixture is then decanted off and the process repeated several times until what remains is cleaned volcanic glass. The glass is washed with alcohol to remove the film of wax and to help dry the glass. It's then put into a labeled plastic bag and archived. On shore, the samples will be analyzed as part of the research we are doing. Mike Perfit, at the Univ. of Florida, Michelle's advisor, and Ken Sims, from WHOI, are the petrologists/geochemists that will direct the analyses of the lava samples we collect.

Close-up of Michelle scooping the wax with the black volcanic glass chips out of the core cutters.

Patrick Hennesy, the Bosun, wrestling the 'Batfish' on the deck tonight during the DSL-120A sonar recovery. The 'Batfish' is the depressor weight that is attached to the fiber optic cable from the ship. The sonar fish is tethered to the 'Batfish' by a 40 meter long piece of buoyant fiber optic cable. This two-body towing system helps to dampen the effects of sea surface waves on the motion of the sonar fish as it is being towed. This dampening helps stabilize the sonar fish and makes for better sidescan sonar records.

The DSL-120A sonar being landed on deck this evening after its last lowering of the cruise.

Pete Collins, one of the DSOG techs, doing the post-dive testing of the sonar fish after it was recovered.

Gary Austin, one of the DSOG techs., cutting the armored fiber optic cable after the sonar was recovered. No more sonar surveying on this leg...!